1 files changed, 116 insertions, 0 deletions
diff --git a/mpm/lib/spi/spidev.c b/mpm/lib/spi/spidev.c
new file mode 100644
index 000000000..929b61aa9
--- /dev/null
+++ b/mpm/lib/spi/spidev.c
@@ -0,0 +1,116 @@
+//
+// Copyright 2017 Ettus Research (National Instruments)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "spidev.h"
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/types.h>
+#include <linux/spi/spidev.h>
+#include <stdio.h>
+
+int init_spi(int *fd, const char *device,
+    const uint32_t mode,
+    const uint32_t speed_hz,
+    const uint8_t bits_per_word,
+    const uint16_t delay_us
+) {
+    int err;
+
+    *fd = open(device, O_RDWR);
+    if (*fd < 0) {
+        fprintf(stderr, "%s: Failed to open device\n", __func__);
+        return err;
+    }
+
+    uint32_t requested_mode = mode;
+    err = ioctl(*fd, SPI_IOC_WR_MODE32, &mode);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed to set mode\n", __func__);
+        return err;;
+    }
+
+    err = ioctl(*fd, SPI_IOC_RD_MODE32, &mode);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed to get mode\n", __func__);
+        return err;
+    }
+    if (requested_mode != mode) {
+        return 2;
+    }
+
+    uint8_t requested_bits_per_word;
+    err = ioctl(*fd, SPI_IOC_WR_BITS_PER_WORD, &bits_per_word);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed to set bits per word\n", __func__);
+        return err;
+    }
+    err = ioctl(*fd, SPI_IOC_RD_BITS_PER_WORD, &bits_per_word);
+    if (err) {
+        fprintf(stderr, "%s: Failed to get bits per word\n", __func__);
+        return err;
+    }
+    if (requested_bits_per_word != bits_per_word) {
+        return 2;
+    }
+
+    uint32_t requested_speed_hz = speed_hz;
+    err = ioctl(*fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed_hz);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed to set speed\n", __func__);
+        return err;
+    }
+    err = ioctl(*fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed_hz);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed to get speed\n", __func__);
+        return err;
+    }
+    if (requested_speed_hz != speed_hz) {
+        return 2;
+    }
+
+    return 0;
+}
+
+int transfer(
+        int fd,
+        uint8_t *tx, uint8_t *rx, uint32_t len,
+        uint32_t speed_hz, uint8_t bits_per_word, uint16_t delay_us
+) {
+    int err;
+
+    struct spi_ioc_transfer tr = {
+        .tx_buf = (unsigned long) tx,
+        .rx_buf = (unsigned long) rx,
+        .len = len,
+        .speed_hz = speed_hz,
+        .delay_usecs = delay_us,
+        .bits_per_word = bits_per_word,
+        .cs_change = 0,
+        .tx_nbits = 1, // Standard SPI
+        .rx_nbits = 1 // Standard SPI
+    };
+
+    err = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed ioctl: %d\n", __func__, err);
+        perror("ioctl: \n");
+	return err;
+    }
+
+    return 0;
+}
+